This invention relates to an electric power generating system capable of absorbing a variable load in response to which the output of a turbine of the generating system can be varied.
Generally, in factories, many kinds of loads are connected to the electric power generating system and the loads vary at a regular or irregular period. For example, in steel manufacturing factories, a finish hot rolling mill, a preliminary hot rolling mill, a cold rolling mill, and a seamless pipe rolling mill constitute variable loads which vary periodically and first and second blooming mills constitute variable loads which vary irregularly. In a steel manufacturing factory the sum of these loads is considered as a periodically variable load. The electric power generating system to which such loads are connected as variable loads must be operated so as to promptly follow up change in the load. This means that the electric power generating system has to be provided with some means for absorbing the variation in the load, particularly in a case where a large load is connected to a generating system which has a considerably small generating capacity such as in a steel manufacturing factory.
Various methods for absorbing a variation in the load have been well known in which the output of a steam turbine is varied and these methods include methods in which steam accumulators or turbine by-pass valves are used or the amount of condensation of the steam exhausted from the turbine is adjusted.
These and other methods or devices of known type for absorbing a load variation accompany various problems as will be hereinafter described in detail.